EACL JVM Caveat evaluator

Runtime dependencies (separate Maven artifacts, not shaded):
- com.exoscale/cel-parser 0.1.8, Exoscale: ISC.
- com.exoscale/antlr-cel 0.1.1, Exoscale and Google CEL grammar: Apache-2.0.
- org.antlr/antlr4-runtime 4.9.2, Terence Parr and Sam Harwell: BSD-3-Clause.

The cel-parser POM also lists MIT. The antlr-cel POM lists MIT and ISC;
its source and vendored CEL grammar carry Apache-2.0. The accompanying
source notices preserve the qualified artifacts' actual notices.
Test fixture adaptations from CEL-spec retain its Apache-2.0 notice.
Versions, revisions, artifact hashes and qualification evidence are recorded
in the repository's exploration/caveats directory.
